Impact of the Outbreak on U.S. Equity Portfolios Based on Markowitz and Index Models

The epidemic occurred in 2019 made a great difference the global financial markets. To explore impact on stock market, this paper builds special portfolios under four specific constraints by using Markowitz and index model. This selected prices of 11 stocks different industries for 20 years then focused two vital indicators to analysis change risk return. One is minimum variance, other maximum sharp ratio. results show that there was an increase both minimal variance ratio during period. Comparing with data before, argues outbreak has caused volatility accelerated shift consumer side equation. fluctuation price can give rise significant speculative activity led simultaneous also found degree restriction almost not change. from facilitate study epidemic’s help people build reasonable portfolio when investing.